MINEOLA — The father of a 7-year-old flower girl, killed along with a chauffeur when a drunken driver plowed into their limousine after a family wedding, angrily branded a judge as cowardly for opting not to impose the maximum sentence in the case.

Although Martin Heidgen was convicted of two counts of murder, acting state Supreme Court Justice Alan Honorof sentenced him to 18 years to life in prison — significantly less than the 25 years to life requested by prosecutors and the victims’ families.

Neil Flynn, whose daughter died in the July 2005 crash, grimaced in disappointment at the sentence before blasting the judge outside the courtroom.

“That judge just did the worst thing he possibly could have done — he compromised,” Mr. Flynn said. “He took a coward’s way out. He didn’t step up and punish the criminal the way he needed to be punished.”

Heidgen, 25, showed no reaction when receiving the sentence, but he earlier offered an apology. About three dozen members of the Flynn family refused to sit in the courtroom during Heidgen’s address.

“Just know that I have already begun a life sentence of anguish, grief and heartbreak long before this day,” he said. “I’m very sorry. I’m very sorry every day, every hour and every minute.”

Mr. Honorof left the bench without explaining his decision. Earlier, eight relatives of 59-year-old limo driver Stanley Rabinowitz and 7-year-old flower girl Katie Flynn stood at a podium to tell Heidgen what they had lost: A loving father and husband. A beloved daughter and granddaughter.

“He deserved a chance to live until a ripe old age,” the driver’s ex-wife, Joyce Rabinowitz, said. “With Stan gone, there is a void in my sons’ lives.”

Katie’s grandfather punctuated his comments by denigrating Heidgen with a four-letter expletive. Neil Flynn, an attorney in private practice, ripped the defendant as a “filthy child killer.”

Four members of the Flynn family and four from the Rabinowitz family stepped up to face Heidgen, whose murder conviction was rare in a drunken-driving case. Heidgen had downed at least 14 drinks when his pickup truck, driving the wrong way on a Long Island parkway, struck the wedding limousine head-on.

Rabinowitz’s sons Nolan and Keith testified, with the latter recalling how his father would often act as a designated driver.

“My father was the guy who would give someone who was drinking too much a ride home for free,” said Keith Rabinowitz.

Katie’s grandmother Denise Tangney, who was seriously injured in the crash, spoke of the devastating impact of the death on her family.

“She is pure joy, and we are poorer for her absence,” she said as relatives sobbed in the gallery.

Prosecutors, who showed jurors a dashboard camera video of the crash several times during the trial, contend Heidgen never tried to stop and turned slightly toward the limousine moments before impact.